Calcium and Blood Pressure

The link between calcium and blood pressure was noticed years ago when
researchers realized that people drinking hard water had less high blood
pressure than those drinking soft water.

Hard water contains more minerals, including calcium.

In fact, a secret weapon against high blood pressure may be calcium-rich foods.

Some
experts contend that high blood pressure is more likely due to a
calcium deficiency than a surplus of sodium and that adequate calcium
intake can cancel the blood-pressure-raising effects of sodium in some
people.

According to Dr. David A. McCarron of Oregon Health
Sciences University, some people simply need more calcium than others to
keep blood pressure normal, and quite often those are people who are
"salt sensitive", that is, whose blood pressure rises from eating too
much sodium.

One theory is that such individuals retain water when
they eat to much sodium, increasing the blood volume, hence raising
blood pressure.

Another
more complex explanation is that when calcium levels in the blood drop,
parathyroid hormone (PTH) is released, which, in turn, causes calcium
to be released from the bones to increase calcium blood levels and PTH
can raise blood pressure.

Whatever the reason, in some people calcium does reduce blood pressure.

Research into Calcium and Blood Pressure

Research into the relationship between calcium and blood pressure at
the University of Texas Health Science Center showed that 800 mg of
calcium a day reduced mild to high blood pressure in 20% of subjects by a
dramatic 20 to 30 points.

Most, however, had small drops and, oddly, blood pressure went up in about 20%.

Another study found that people under age 40 may cut their chances of developing high blood pressure by eating enough calcium.

In
fact, the chances of high blood pressure went down an average 20% for
each 1,000 mg. of calcium consumed per day in moderate drinkers (not
more than one drink a day) who were not overweight.

In people who
drank less alcohol, the risk plunged by 40 %. Apparently, alcohol tends
to counteract calcium's powers to lower blood pressure, said study
author James H. Dwyer of the University of Southern California School of
Medicine in Los Angeles.

As mentioned earlier, some people
respond better to supplemental calcium than others. Apart from people
who are salt sensitive and individuals with a high sodium intake, others
include African-Americans, elderly, pregnant women, menopausal women,
and those with Type II diabetes.

Food Sources of Calcium

Low-fat dairy products

Leafy greens (i.e. kale, collard, turnip, mustard greens)

Broccoli

Canned Sardines (with bones)

Canned Salmon (with bones)

Calcium fortified Orange Juice

Tofu (if made with calcium carbonate)

Milk and dairy foods, of course, are rich in calcium and the American
Heart Association has reported that women who consume more low-fat or
fat free milk products, and/or had diets high in calcium, are far less
likely to suffer from high blood pressure than women with lower calcium
levels in their diets.

But milk and dairy products can cause
digestive problems and allergies in many people and, of course, the
full-fat varieties are, well ... full of fat (especially saturated fat),
so widen your horizons and consider the other sources of calcium and
try to include them in your diet as much as you can.

Calcium and Vitamin D

The ability of the body to use calcium depends not only on its intake but also on its absorption. The amount absorbed depends on the food, but is normally around 20-30%.

For better results you need to supplement calcium along with vitamin D.

Vitamin D aids the absorption of calcium from the small intestine and it controls the deposition of calcium in bones.

One study supplemented women 1200 mg of calcium for blood pressure.

When they added 800 IU of vitamin D, systolic blood pressure decreased an average of 9.3%.

Many studies show that appropriate levels of vitamin D are required for the metabolism and absorption of calcium.

Thus,
while studies indicate that higher amounts of calcium and dairy
products result in lower blood pressure, they also caution that
sufficient vitamin D must be a part of the diet as well.

So people
may be eating enough calcium-rich foods and still suffer with high
blood pressure because their intake of vitamin D is not adequate.

Very
few foods are naturally rich in vitamin D. Milk is most often fortified
with 125 IU of vitamin D per glass. There is also some vitamin D in
eggs, organ meats, and fish such as salmon, sardines, and herring.

Vitamin
D is also manufactured in the skin right after direct exposure to
sunlight. Sunlight exposure to the hands, face and arms for as little as
10-30 minutes, 2-3 times per week is helpful to produce vitamin D
during the summer months.

Calcium and Magnesium

Magnesium works along with calcium not only for maintaining bone density but also for the good functioning of blood vessels.

The average diet is relatively high in calcium but deficient in magnesium, because milk, a major source of calcium, is not a very good source of magnesium.

There's no point in increasing calcium intake if magnesium status is poor. Without magnesium, calcium absorption will also be poor.

Both minerals are present in green leafy vegetables, nuts and seeds. And if you supplement with calcium, you need to supplement with magnesium as well.

This article is the last in the series of healing foods for high blood pressure. Go back at the beginning by clicking on Causes of High Blood Pressure or choose one article from the list below.